Field of the Disclosure
The present application relates to a guide panel. Also, the present application relates to a backlight unit and a liquid crystal display device which each include the guide panel.
Description of the Related Art
The general liquid crystal display device displays a desired image by controlling light transmittances of liquid crystal cells, which are arranged in a matrix shape, according to image information signals. In other words, the liquid crystal display device displays images on a liquid crystal panel using light irradiated from a backlight unit.
The liquid crystal display device using the above-mentioned principle has features of thinner, lighter weight, lower power consumption and lower driving voltage. As such, the liquid crystal display device is being widely applied in a variety of fields.
For example, the liquid crystal display device is being used in office automation appliances, audio/video appliances and so on.
Such a liquid crystal display device controls light transmittances of liquid crystal cells using signals which are applied to a plurality of control switches arranged in a matrix shape. As such, a desired image is displayed on a screen.
Nowadays, the liquid crystal display device is being widely applied to monitors of the computers, television receivers, portable display devices, which include display devices of navigation systems for vehicles and mobile phones, and so on.
Such a liquid crystal display device is a non-emissive type device which displays images by adjusting the quantity of light applied from an external light source. As such, the liquid crystal display device is necessary for a backlight unit which includes a separated light source and applies light to the liquid crystal panel.
The backlight unit includes: light emitting diodes (LEDs) used as a light source; a light guide plate disposed opposite to a light emission surface of the LEDs; and a plurality of optical sheets disposed on the light guide plate. Also, the backlight unit includes a guide panel configured to support the liquid crystal panel and prevent light leakage.
FIGS. 1 and 2 are cross-sectional views showing backlight units according to the related art.
Referring to FIG. 1, a backlight unit 10 of the related art includes a bottom cover 11; a guide panel 12 disposed on edges of the bottom cover 11; and a reflective sheet 13, a light guide plate 14, optical sheets 15 and a liquid crystal panel 16 received into the bottom cover 11. The backlight unit 10 further includes a light leakage prevention tape 17 encompassing an upper surface and side surfaces of the guide panel 12.
Such a guide panel 12 used in the related art backlight unit 10 is formed from a mold material. As such, not only the mold guide panel 12 must have large thicknesses t1 but also the width t2 of an externally exposed non-display area must increase. Due to this, it is difficult to realize slimness of the backlight unit and a narrow bezel.
Moreover, light can leak out between the liquid crystal panel 16 and the optical sheets 15. In order to prevent such a light leakage phenomenon, the light leakage prevention tape 17 is additionally used. As such, the fabrication cost of the backlight unit 10 must increase.
Referring to FIG. 2, another backlight unit 10 of the related art includes a bottom cover 11; a guide panel 12 disposed on edges of the bottom cover 11; and a reflective sheet 13, a light guide plate 14, optical sheets 15 and a liquid crystal panel 16 received into the bottom cover 11. Also, another backlight unit 10 further includes a light leakage prevention tape 17 encompassing an upper surface and side surfaces of the guide panel 12.
In order to realize slimness and the narrow bezel, the guide panel 12 used in another backlight unit 10 is formed from a press material. The guide panel 12 of the press material has a thinner thickness compared to that of the mold guide panel. However, the guide panel 12 cannot secure uniformity and must have a lower strength due to its thin thickness t1. As such, a circular part of the guide panel 12 represented by an alternate long and short dash line must be bent toward the inner direction of another backlight unit 10. Due to this, the guide panel 12 formed a metal material must damage a side surface (or an edge) of the liquid crystal panel 16. To this end, it must be necessary to use an additional pad member 18. Also, the guide panel 12 formed from the press material must cause light to leak because of its high reflectance. To address this matter, a light leak prevention tape 17 must be used in the backlight unit 10. Accordingly, the fabrication cost of the backlight unit 10 must increase. Moreover, because the width t2 of an externally exposed non-display area must increase, it is difficult to realize slimness of the backlight unit and a narrow bezel.